The present invention relates to a snow discharge device in a snow removal machine, and more particularly to a means for adjusting a pivotally mounted deflector at the upper-end of a discharge chute in a snow removal machine.
The function of a snow removal machine is to remove large amounts of snow particles from one area and to deposit them in another. When the machine is used in tight quarters, for instance, the snow particles must be directed forwardly of the machine. At other times, it may be necessary to direct the snow particles laterally of the machine, sometimes over and beyond obstacles or other obstructions, and sometimes into a head wind or a side wind.
There are various commercially available power-operated snow removal machines which include a snow gathering housing at the front of a two-wheel or four-wheel chassis with rotatable snow removal blades for forcing snow particles into an upwardly directed snow discharge chute which is rotatable about an upright axis. The upper end of the snow discharge chute includes a pivotally mounted deflector, and angular adjustment of the chute enables snow discharge to one side or the other of the path of movement.
The operator of such a snow removal machine must safely direct the prime mover, set an appropriate angle on the deflector so that a head wind or a side wind will not inundate him with snow, and control the rotation of the chute so that the path of emitted snow particles will be deposited in their intended place. It is frequently necessary to make immediate and effective adjustments to the chute and/or to the deflector so that the snow particles can be immediately directed in their intended path. When operating in extremely windy conditions, immediate and accurate deflector adjustments are frequently needed, or a head wind may inundate the operator of the mechanism with the snow particles which are being cleared. In addition, when a snow removal device is being used closely adjacent to a hedge or to walls, to buildings or other obstructions or obstacles, it is frequently necessary to take immediate and effective measures to adjust the path of the snow particles so that the snow particles may be directed in either a horizontal path to the side or in an arcuate path over and beyond the obstacles. In the northern states, where snow on the level may accumulate to a depth of three to four feet, successful snow plowing necessitates throwing newly fallen snow over accumulated banks of snow which become small hills before the winter months are over.
In the past, it has been conventional to provide manually accessible means adjacent the operator's control station for angularly adjusting the discharge chute. On the other hand, it has not always been usual to provide remote control means for adjusting the deflector from the operator's control station. Instead, it has often been a requirement that the deflector must be adjusted locally at the position of its mounting to the chute. However, such local adjustment requires that operation of the machine be discontinued and the machine switched off, since the moving snow removal blades or rotating snow removal screw presents a serious potential hazard to the operator's person. In addition, local adjustment places the operator in the path of potentially hazardous materials normally being projected through the chute. Having to cease operation in order to manually perform adjustments is inefficient and completely unnecessary.
In some machines, however, provision has been made for adjustment of the discharge deflector remotely from an operator's control station. For example, U.S. Pat. No. 2,971,279 relates to a rotary snow plow in which a deflector is adjustable by a loose cable arranged in a cable guide which is offset from the axis of rotation of the chute. U.S. Pat. No. 3,299,546 relates to a rotary snow plow with cable means for adjusting a deflector on a discharge chute, including a loose cable on a stationary cable guide pulley and additional guide rollers for holding the cable on the pulley when the chute is angularly directed toward opposite sides of the machine. U.S. Pat. No. 3,510,171 relates to a snow removing machine in which a deflector is adjustable by a Bowden cable in a sheath. U.S. Pat. No. 2,741,512 relates to a forage harvester with an adjustable deflector controlled by a cable mechanism held by a ratchet device.
There are, however, various inherent disadvantages associated with the deflector adjustment remote controls of the type described above. The prior art fails to show a means for maintaining a preselected horizontal elevation of the deflector whenever the chute to which it is attached has been rotated with respect to the chassis of the snow removing machine. Whenever the direction of the chute is changed, the deflector is also changed, which thereby results in a change in the altitude of the snow particles which are expelled.
My U.S. Pat. Nos. 3,867,773 and 3,879,866 each show a related structure for controlling the adjustment of a deflector in such manner that angular chute adjustment does not alter the selected position of deflector adjustment.